The present invention relates to an ink jet recording process for recording an image by discharging ink onto a recording medium and to an ink jet recording apparatus. More particularly, the invention relates to an ink jet recording process containing an overcoat step of forming a protective layer on an image and an ink jet recording apparatus suitable for the recording process.
The ink jet recording process is a recording process in which ink droplets are discharged through minute nozzles according to image information, and allowed to adhere to a recording medium, thereby making a print. By the recent innovative progress of the ink jet recording technology, the ink jet prints have reached a high level comparable in image quality to silver salt photographs, but have come short of the silver salt photographs yet in image fastness in the present state. In recent years, with the expansion of the ink jet recording technology to digital photograph service, commercial print applications and the like, importance has increasingly become to be attached to improvements in image fastness.
Further, as recording technology which can enhance image fastness and luster, there has been known overcoat treatment in which a recorded image is covered with a protective layer such as a transparent film. The overcoat treatment has also attracted attention in the ink jet recording field as a technique having the possibility that high image quality and high image fastness comparable to the silver salt photographs can be achieved, and various improved techniques have been proposed with respect to the materials and structures of the protective layers, forming processes or the like.
It is as described above that high image quality and high image fastness are required for the ink jet recording process. However, as a premise for that, it is needed that entered image information such as image information electronically taken in or accumulated in computers or networks, or image information taken in with digital cameras, digital videos or scanners is faithfully reproduced. For example, in a recording system provided with a host computer such as a personal computer and a recording device such as a printer connected thereto, a general ink jet recording system, the host computer conducts necessary processing such as binarization to the entered image information to form print data, which are supplied to a printer together with data indicating the kind of recording medium. The printer is constituted so as to perform the ejection control of ink corresponding to these data, thereby being able to reproduce approximately faithfully on the recording medium an image corresponding to the entered image information.
However, when the above-mentioned overcoat treatment technology is incorporated in the general ink jet recording system in order to achieve high image quality and high image fastness, the problem has been encountered that the image corresponding to the entered image information cannot be obtained. This is caused by changes in color characteristics generated by the overcoat treatment of the image normally output onto the recording medium (the image corresponding to the entered image information). Although a color reproduction region is enlarged with an increase in image density, changes come out in hue and contrast ratio of the image, resulting in failure to faithfully reproduce the entered image information. The shading ratio of the whole image changes to deflect from an intended expression, or the properties and degree of changes vary according to each color and shading. Accordingly, in the case of a color image, the balance of the whole image is lost. In some very extreme cases, such changes in hue that a blue printed area is tinged with green are also observed. It can be considered that it is a fetal defect of a recording system that the image corresponding to the entered image information cannot be obtained as described above.
The invention has been made in view of such problems, and an object of the invention is to provide an ink jet recording process which can faithfully reproduce entered image information, and can achieve high image quality and high image fastness comparable to a silver salt photograph. Another object of the invention is to provide an ink jet recording apparatus suitable for the recording process.
Other objects and effects of the invention will become apparent from the following description.
The above-mentioned objects of the invention have been achieved by providing the following ink jet recording process and ink jet recording apparatus.
An ink jet recording process comprising an ink jet recording step of discharging one or more kinds of inks based on entered image information to record an image of one or more colors on a recording medium, and an overcoat step of forming a protective layer for covering the image on the recording medium, wherein control tables corresponding to changes in characteristics of the color(s) which occur by covering the color(s) output onto the above-mentioned recording medium with the above-mentioned protective layer are prepared beforehand, and in the above-mentioned ink jet recording step, discharge control of the ink(s) is performed in accordance with the above-mentioned control tables to record the image, thereby making it possible to faithfully reproduce the entered image information; and
An ink jet recording apparatus comprising an ink jet recording device for discharging one or more kinds of inks based on entered image information to record an image of one or more colors on a recording medium, and an overcoat device for forming a protective layer for covering the image on the recording medium, wherein the ink jet recording apparatus further comprises control tables corresponding to changes in characteristics of the color(s) which occur by covering the color(s) output onto the above-mentioned recording medium with the above-mentioned protective layer, and the above-mentioned ink jet recording device performs discharge control of the ink(s) in accordance with the above-mentioned control tables to record the image, thereby making it possible to faithfully reproduce the entered image information.